arch/arm/mach-omap2/voltage.c

   1 /*
   2  * OMAP3/OMAP4 Voltage Management Routines
   3  *
   4  * Author: Thara Gopinath       <thara@ti.com>
   5  *
   6  * Copyright (C) 2007 Texas Instruments, Inc.
   7  * Rajendra Nayak <rnayak@ti.com>
   8  * Lesly A M <x0080970@ti.com>
   9  *
  10  * Copyright (C) 2008, 2011 Nokia Corporation
  11  * Kalle Jokiniemi
  12  * Paul Walmsley
  13  *
  14  * Copyright (C) 2010 Texas Instruments, Inc.
  15  * Thara Gopinath <thara@ti.com>
  16  *
  17  * This program is free software; you can redistribute it and/or modify
  18  * it under the terms of the GNU General Public License version 2 as
  19  * published by the Free Software Foundation.
  20  */
  21
  22 #include <linux/delay.h>
  23 #include <linux/io.h>
  24 #include <linux/clk.h>
  25 #include <linux/err.h>
  26 #include <linux/export.h>
  27 #include <linux/debugfs.h>
  28 #include <linux/slab.h>
  29
  30 #include <plat/common.h>
  31
  32 #include "prm-regbits-34xx.h"
  33 #include "prm-regbits-44xx.h"
  34 #include "prm44xx.h"
  35 #include "prcm44xx.h"
  36 #include "prminst44xx.h"
  37 #include "control.h"
  38
  39 #include "voltage.h"
  40
  41 #include "vc.h"
  42 #include "vp.h"
  43
  44 #define VOLTAGE_DIR_SIZE        16
  45
  46
  47 static struct omap_vdd_info **vdd_info;
  48
  49 /*
  50  * Number of scalable voltage domains.
  51  */
  52 static int nr_scalable_vdd;
  53
  54 /* XXX document */
  55 static s16 prm_mod_offs;
  56 static s16 prm_irqst_ocp_mod_offs;
  57
  58 static struct dentry *voltage_dir;
  59
  60 /* Init function pointers */
  61 static int vp_forceupdate_scale_voltage(struct omap_vdd_info *vdd,
  62                                         unsigned long target_volt);
  63
  64 static u32 omap3_voltage_read_reg(u16 mod, u8 offset)
  65 {
  66         return omap2_prm_read_mod_reg(mod, offset);
  67 }
  68
  69 static void omap3_voltage_write_reg(u32 val, u16 mod, u8 offset)
  70 {
  71         omap2_prm_write_mod_reg(val, mod, offset);
  72 }
  73
  74 static u32 omap4_voltage_read_reg(u16 mod, u8 offset)
  75 {
  76         return omap4_prminst_read_inst_reg(OMAP4430_PRM_PARTITION,
  77                                         mod, offset);
  78 }
  79
  80 static void omap4_voltage_write_reg(u32 val, u16 mod, u8 offset)
  81 {
  82         omap4_prminst_write_inst_reg(val, OMAP4430_PRM_PARTITION, mod, offset);
  83 }
  84
  85 static int __init _config_common_vdd_data(struct omap_vdd_info *vdd)
  86 {
  87         char *sys_ck_name;
  88         struct clk *sys_ck;
  89         u32 sys_clk_speed, timeout_val, waittime;
  90
  91         /*
  92          * XXX Clockfw should handle this, or this should be in a
  93          * struct record
  94          */
  95         if (cpu_is_omap24xx() || cpu_is_omap34xx())
  96                 sys_ck_name = "sys_ck";
  97         else if (cpu_is_omap44xx())
  98                 sys_ck_name = "sys_clkin_ck";
  99         else
 100                 return -EINVAL;
 101
 102         /*
 103          * Sys clk rate is require to calculate vp timeout value and
 104          * smpswaittimemin and smpswaittimemax.
 105          */
 106         sys_ck = clk_get(NULL, sys_ck_name);
 107         if (IS_ERR(sys_ck)) {
 108                 pr_warning("%s: Could not get the sys clk to calculate"
 109                         "various vdd_%s params\n", __func__, vdd->voltdm.name);
 110                 return -EINVAL;
 111         }
 112         sys_clk_speed = clk_get_rate(sys_ck);
 113         clk_put(sys_ck);
 114         /* Divide to avoid overflow */
 115         sys_clk_speed /= 1000;
 116
 117         /* Generic voltage parameters */
 118         vdd->volt_scale = vp_forceupdate_scale_voltage;
 119         vdd->vp_enabled = false;
 120
 121         vdd->vp_rt_data.vpconfig_erroroffset =
 122                 (vdd->pmic_info->vp_erroroffset <<
 123                  vdd->vp_data->vp_common->vpconfig_erroroffset_shift);
 124
 125         timeout_val = (sys_clk_speed * vdd->pmic_info->vp_timeout_us) / 1000;
 126         vdd->vp_rt_data.vlimitto_timeout = timeout_val;
 127         vdd->vp_rt_data.vlimitto_vddmin = vdd->pmic_info->vp_vddmin;
 128         vdd->vp_rt_data.vlimitto_vddmax = vdd->pmic_info->vp_vddmax;
 129
 130         waittime = ((vdd->pmic_info->step_size / vdd->pmic_info->slew_rate) *
 131                                 sys_clk_speed) / 1000;
 132         vdd->vp_rt_data.vstepmin_smpswaittimemin = waittime;
 133         vdd->vp_rt_data.vstepmax_smpswaittimemax = waittime;
 134         vdd->vp_rt_data.vstepmin_stepmin = vdd->pmic_info->vp_vstepmin;
 135         vdd->vp_rt_data.vstepmax_stepmax = vdd->pmic_info->vp_vstepmax;
 136
 137         return 0;
 138 }
 139
 140 /* Voltage debugfs support */
 141 static int vp_volt_debug_get(void *data, u64 *val)
 142 {
 143         struct omap_vdd_info *vdd = (struct omap_vdd_info *) data;
 144         u8 vsel;
 145
 146         if (!vdd) {
 147                 pr_warning("Wrong paramater passed\n");
 148                 return -EINVAL;
 149         }
 150
 151         vsel = vdd->read_reg(prm_mod_offs, vdd->vp_data->voltage);
 152
 153         if (!vdd->pmic_info->vsel_to_uv) {
 154                 pr_warning("PMIC function to convert vsel to voltage"
 155                         "in uV not registerd\n");
 156                 return -EINVAL;
 157         }
 158
 159         *val = vdd->pmic_info->vsel_to_uv(vsel);
 160         return 0;
 161 }
 162
 163 static int nom_volt_debug_get(void *data, u64 *val)
 164 {
 165         struct omap_vdd_info *vdd = (struct omap_vdd_info *) data;
 166
 167         if (!vdd) {
 168                 pr_warning("Wrong paramater passed\n");
 169                 return -EINVAL;
 170         }
 171
 172         *val = omap_voltage_get_nom_volt(&vdd->voltdm);
 173
 174         return 0;
 175 }
 176
 177 DEFINE_SIMPLE_ATTRIBUTE(vp_volt_debug_fops, vp_volt_debug_get, NULL, "%llu\n");
 178 DEFINE_SIMPLE_ATTRIBUTE(nom_volt_debug_fops, nom_volt_debug_get, NULL,
 179                                                                 "%llu\n");
 180 static void vp_latch_vsel(struct omap_vdd_info *vdd)
 181 {
 182         u32 vpconfig;
 183         unsigned long uvdc;
 184         char vsel;
 185
 186         uvdc = omap_voltage_get_nom_volt(&vdd->voltdm);
 187         if (!uvdc) {
 188                 pr_warning("%s: unable to find current voltage for vdd_%s\n",
 189                         __func__, vdd->voltdm.name);
 190                 return;
 191         }
 192
 193         if (!vdd->pmic_info || !vdd->pmic_info->uv_to_vsel) {
 194                 pr_warning("%s: PMIC function to convert voltage in uV to"
 195                         " vsel not registered\n", __func__);
 196                 return;
 197         }
 198
 199         vsel = vdd->pmic_info->uv_to_vsel(uvdc);
 200
 201         vpconfig = vdd->read_reg(prm_mod_offs, vdd->vp_data->vpconfig);
 202         vpconfig &= ~(vdd->vp_data->vp_common->vpconfig_initvoltage_mask |
 203                         vdd->vp_data->vp_common->vpconfig_initvdd);
 204         vpconfig |= vsel << vdd->vp_data->vp_common->vpconfig_initvoltage_shift;
 205
 206         vdd->write_reg(vpconfig, prm_mod_offs, vdd->vp_data->vpconfig);
 207
 208         /* Trigger initVDD value copy to voltage processor */
 209         vdd->write_reg((vpconfig | vdd->vp_data->vp_common->vpconfig_initvdd),
 210                        prm_mod_offs, vdd->vp_data->vpconfig);
 211
 212         /* Clear initVDD copy trigger bit */
 213         vdd->write_reg(vpconfig, prm_mod_offs, vdd->vp_data->vpconfig);
 214 }
 215
 216 /* Generic voltage init functions */
 217 static void __init vp_init(struct omap_vdd_info *vdd)
 218 {
 219         u32 vp_val;
 220
 221         if (!vdd->read_reg || !vdd->write_reg) {
 222                 pr_err("%s: No read/write API for accessing vdd_%s regs\n",
 223                         __func__, vdd->voltdm.name);
 224                 return;
 225         }
 226
 227         vp_val = vdd->vp_rt_data.vpconfig_erroroffset |
 228                 (vdd->vp_rt_data.vpconfig_errorgain <<
 229                 vdd->vp_data->vp_common->vpconfig_errorgain_shift) |
 230                 vdd->vp_data->vp_common->vpconfig_timeouten;
 231         vdd->write_reg(vp_val, prm_mod_offs, vdd->vp_data->vpconfig);
 232
 233         vp_val = ((vdd->vp_rt_data.vstepmin_smpswaittimemin <<
 234                 vdd->vp_data->vp_common->vstepmin_smpswaittimemin_shift) |
 235                 (vdd->vp_rt_data.vstepmin_stepmin <<
 236                 vdd->vp_data->vp_common->vstepmin_stepmin_shift));
 237         vdd->write_reg(vp_val, prm_mod_offs, vdd->vp_data->vstepmin);
 238
 239         vp_val = ((vdd->vp_rt_data.vstepmax_smpswaittimemax <<
 240                 vdd->vp_data->vp_common->vstepmax_smpswaittimemax_shift) |
 241                 (vdd->vp_rt_data.vstepmax_stepmax <<
 242                 vdd->vp_data->vp_common->vstepmax_stepmax_shift));
 243         vdd->write_reg(vp_val, prm_mod_offs, vdd->vp_data->vstepmax);
 244
 245         vp_val = ((vdd->vp_rt_data.vlimitto_vddmax <<
 246                 vdd->vp_data->vp_common->vlimitto_vddmax_shift) |
 247                 (vdd->vp_rt_data.vlimitto_vddmin <<
 248                 vdd->vp_data->vp_common->vlimitto_vddmin_shift) |
 249                 (vdd->vp_rt_data.vlimitto_timeout <<
 250                 vdd->vp_data->vp_common->vlimitto_timeout_shift));
 251         vdd->write_reg(vp_val, prm_mod_offs, vdd->vp_data->vlimitto);
 252 }
 253
 254 static void __init vdd_debugfs_init(struct omap_vdd_info *vdd)
 255 {
 256         char *name;
 257
 258         name = kzalloc(VOLTAGE_DIR_SIZE, GFP_KERNEL);
 259         if (!name) {
 260                 pr_warning("%s: Unable to allocate memory for debugfs"
 261                         " directory name for vdd_%s",
 262                         __func__, vdd->voltdm.name);
 263                 return;
 264         }
 265         strcpy(name, "vdd_");
 266         strcat(name, vdd->voltdm.name);
 267
 268         vdd->debug_dir = debugfs_create_dir(name, voltage_dir);
 269         kfree(name);
 270         if (IS_ERR(vdd->debug_dir)) {
 271                 pr_warning("%s: Unable to create debugfs directory for"
 272                         " vdd_%s\n", __func__, vdd->voltdm.name);
 273                 vdd->debug_dir = NULL;
 274                 return;
 275         }
 276
 277         (void) debugfs_create_x16("vp_errorgain", S_IRUGO, vdd->debug_dir,
 278                                 &(vdd->vp_rt_data.vpconfig_errorgain));
 279         (void) debugfs_create_x16("vp_smpswaittimemin", S_IRUGO,
 280                                 vdd->debug_dir,
 281                                 &(vdd->vp_rt_data.vstepmin_smpswaittimemin));
 282         (void) debugfs_create_x8("vp_stepmin", S_IRUGO, vdd->debug_dir,
 283                                 &(vdd->vp_rt_data.vstepmin_stepmin));
 284         (void) debugfs_create_x16("vp_smpswaittimemax", S_IRUGO,
 285                                 vdd->debug_dir,
 286                                 &(vdd->vp_rt_data.vstepmax_smpswaittimemax));
 287         (void) debugfs_create_x8("vp_stepmax", S_IRUGO, vdd->debug_dir,
 288                                 &(vdd->vp_rt_data.vstepmax_stepmax));
 289         (void) debugfs_create_x8("vp_vddmax", S_IRUGO, vdd->debug_dir,
 290                                 &(vdd->vp_rt_data.vlimitto_vddmax));
 291         (void) debugfs_create_x8("vp_vddmin", S_IRUGO, vdd->debug_dir,
 292                                 &(vdd->vp_rt_data.vlimitto_vddmin));
 293         (void) debugfs_create_x16("vp_timeout", S_IRUGO, vdd->debug_dir,
 294                                 &(vdd->vp_rt_data.vlimitto_timeout));
 295         (void) debugfs_create_file("curr_vp_volt", S_IRUGO, vdd->debug_dir,
 296                                 (void *) vdd, &vp_volt_debug_fops);
 297         (void) debugfs_create_file("curr_nominal_volt", S_IRUGO,
 298                                 vdd->debug_dir, (void *) vdd,
 299                                 &nom_volt_debug_fops);
 300 }
 301
 302 /* Voltage scale and accessory APIs */
 303 static int _pre_volt_scale(struct omap_vdd_info *vdd,
 304                 unsigned long target_volt, u8 *target_vsel, u8 *current_vsel)
 305 {
 306         struct omap_volt_data *volt_data;
 307         const struct omap_vc_common_data *vc_common;
 308         const struct omap_vp_common_data *vp_common;
 309         u32 vc_cmdval, vp_errgain_val;
 310
 311         vc_common = vdd->vc_data->vc_common;
 312         vp_common = vdd->vp_data->vp_common;
 313
 314         /* Check if suffiecient pmic info is available for this vdd */
 315         if (!vdd->pmic_info) {
 316                 pr_err("%s: Insufficient pmic info to scale the vdd_%s\n",
 317                         __func__, vdd->voltdm.name);
 318                 return -EINVAL;
 319         }
 320
 321         if (!vdd->pmic_info->uv_to_vsel) {
 322                 pr_err("%s: PMIC function to convert voltage in uV to"
 323                         "vsel not registered. Hence unable to scale voltage"
 324                         "for vdd_%s\n", __func__, vdd->voltdm.name);
 325                 return -ENODATA;
 326         }
 327
 328         if (!vdd->read_reg || !vdd->write_reg) {
 329                 pr_err("%s: No read/write API for accessing vdd_%s regs\n",
 330                         __func__, vdd->voltdm.name);
 331                 return -EINVAL;
 332         }
 333
 334         /* Get volt_data corresponding to target_volt */
 335         volt_data = omap_voltage_get_voltdata(&vdd->voltdm, target_volt);
 336         if (IS_ERR(volt_data))
 337                 volt_data = NULL;
 338
 339         *target_vsel = vdd->pmic_info->uv_to_vsel(target_volt);
 340         *current_vsel = vdd->read_reg(prm_mod_offs, vdd->vp_data->voltage);
 341
 342         /* Setting the ON voltage to the new target voltage */
 343         vc_cmdval = vdd->read_reg(prm_mod_offs, vdd->vc_data->cmdval_reg);
 344         vc_cmdval &= ~vc_common->cmd_on_mask;
 345         vc_cmdval |= (*target_vsel << vc_common->cmd_on_shift);
 346         vdd->write_reg(vc_cmdval, prm_mod_offs, vdd->vc_data->cmdval_reg);
 347
 348         /* Setting vp errorgain based on the voltage */
 349         if (volt_data) {
 350                 vp_errgain_val = vdd->read_reg(prm_mod_offs,
 351                                                vdd->vp_data->vpconfig);
 352                 vdd->vp_rt_data.vpconfig_errorgain = volt_data->vp_errgain;
 353                 vp_errgain_val &= ~vp_common->vpconfig_errorgain_mask;
 354                 vp_errgain_val |= vdd->vp_rt_data.vpconfig_errorgain <<
 355                         vp_common->vpconfig_errorgain_shift;
 356                 vdd->write_reg(vp_errgain_val, prm_mod_offs,
 357                                vdd->vp_data->vpconfig);
 358         }
 359
 360         return 0;
 361 }
 362
 363 static void _post_volt_scale(struct omap_vdd_info *vdd,
 364                 unsigned long target_volt, u8 target_vsel, u8 current_vsel)
 365 {
 366         u32 smps_steps = 0, smps_delay = 0;
 367
 368         smps_steps = abs(target_vsel - current_vsel);
 369         /* SMPS slew rate / step size. 2us added as buffer. */
 370         smps_delay = ((smps_steps * vdd->pmic_info->step_size) /
 371                         vdd->pmic_info->slew_rate) + 2;
 372         udelay(smps_delay);
 373
 374         vdd->curr_volt = target_volt;
 375 }
 376
 377 /* vc_bypass_scale_voltage - VC bypass method of voltage scaling */
 378 static int vc_bypass_scale_voltage(struct omap_vdd_info *vdd,
 379                 unsigned long target_volt)
 380 {
 381         u32 loop_cnt = 0, retries_cnt = 0;
 382         u32 vc_valid, vc_bypass_val_reg, vc_bypass_value;
 383         u8 target_vsel, current_vsel;
 384         int ret;
 385
 386         ret = _pre_volt_scale(vdd, target_volt, &target_vsel, &current_vsel);
 387         if (ret)
 388                 return ret;
 389
 390         vc_valid = vdd->vc_data->vc_common->valid;
 391         vc_bypass_val_reg = vdd->vc_data->vc_common->bypass_val_reg;
 392         vc_bypass_value = (target_vsel << vdd->vc_data->vc_common->data_shift) |
 393                         (vdd->pmic_info->pmic_reg <<
 394                         vdd->vc_data->vc_common->regaddr_shift) |
 395                         (vdd->pmic_info->i2c_slave_addr <<
 396                         vdd->vc_data->vc_common->slaveaddr_shift);
 397
 398         vdd->write_reg(vc_bypass_value, prm_mod_offs, vc_bypass_val_reg);
 399         vdd->write_reg(vc_bypass_value | vc_valid, prm_mod_offs,
 400                        vc_bypass_val_reg);
 401
 402         vc_bypass_value = vdd->read_reg(prm_mod_offs, vc_bypass_val_reg);
 403         /*
 404          * Loop till the bypass command is acknowledged from the SMPS.
 405          * NOTE: This is legacy code. The loop count and retry count needs
 406          * to be revisited.
 407          */
 408         while (!(vc_bypass_value & vc_valid)) {
 409                 loop_cnt++;
 410
 411                 if (retries_cnt > 10) {
 412                         pr_warning("%s: Retry count exceeded\n", __func__);
 413                         return -ETIMEDOUT;
 414                 }
 415
 416                 if (loop_cnt > 50) {
 417                         retries_cnt++;
 418                         loop_cnt = 0;
 419                         udelay(10);
 420                 }
 421                 vc_bypass_value = vdd->read_reg(prm_mod_offs,
 422                                                 vc_bypass_val_reg);
 423         }
 424
 425         _post_volt_scale(vdd, target_volt, target_vsel, current_vsel);
 426         return 0;
 427 }
 428
 429 /* VP force update method of voltage scaling */
 430 static int vp_forceupdate_scale_voltage(struct omap_vdd_info *vdd,
 431                 unsigned long target_volt)
 432 {
 433         u32 vpconfig;
 434         u8 target_vsel, current_vsel, prm_irqst_reg;
 435         int ret, timeout = 0;
 436
 437         ret = _pre_volt_scale(vdd, target_volt, &target_vsel, &current_vsel);
 438         if (ret)
 439                 return ret;
 440
 441         prm_irqst_reg = vdd->vp_data->prm_irqst_data->prm_irqst_reg;
 442
 443         /*
 444          * Clear all pending TransactionDone interrupt/status. Typical latency
 445          * is <3us
 446          */
 447         while (timeout++ < VP_TRANXDONE_TIMEOUT) {
 448                 vdd->write_reg(vdd->vp_data->prm_irqst_data->tranxdone_status,
 449                                prm_irqst_ocp_mod_offs, prm_irqst_reg);
 450                 if (!(vdd->read_reg(prm_irqst_ocp_mod_offs, prm_irqst_reg) &
 451                       vdd->vp_data->prm_irqst_data->tranxdone_status))
 452                         break;
 453                 udelay(1);
 454         }
 455         if (timeout >= VP_TRANXDONE_TIMEOUT) {
 456                 pr_warning("%s: vdd_%s TRANXDONE timeout exceeded."
 457                         "Voltage change aborted", __func__, vdd->voltdm.name);
 458                 return -ETIMEDOUT;
 459         }
 460
 461         /* Configure for VP-Force Update */
 462         vpconfig = vdd->read_reg(prm_mod_offs, vdd->vp_data->vpconfig);
 463         vpconfig &= ~(vdd->vp_data->vp_common->vpconfig_initvdd |
 464                         vdd->vp_data->vp_common->vpconfig_forceupdate |
 465                         vdd->vp_data->vp_common->vpconfig_initvoltage_mask);
 466         vpconfig |= ((target_vsel <<
 467                         vdd->vp_data->vp_common->vpconfig_initvoltage_shift));
 468         vdd->write_reg(vpconfig, prm_mod_offs, vdd->vp_data->vpconfig);
 469
 470         /* Trigger initVDD value copy to voltage processor */
 471         vpconfig |= vdd->vp_data->vp_common->vpconfig_initvdd;
 472         vdd->write_reg(vpconfig, prm_mod_offs, vdd->vp_data->vpconfig);
 473
 474         /* Force update of voltage */
 475         vpconfig |= vdd->vp_data->vp_common->vpconfig_forceupdate;
 476         vdd->write_reg(vpconfig, prm_mod_offs, vdd->vp_data->vpconfig);
 477
 478         /*
 479          * Wait for TransactionDone. Typical latency is <200us.
 480          * Depends on SMPSWAITTIMEMIN/MAX and voltage change
 481          */
 482         timeout = 0;
 483         omap_test_timeout((vdd->read_reg(prm_irqst_ocp_mod_offs, prm_irqst_reg) &
 484                            vdd->vp_data->prm_irqst_data->tranxdone_status),
 485                           VP_TRANXDONE_TIMEOUT, timeout);
 486         if (timeout >= VP_TRANXDONE_TIMEOUT)
 487                 pr_err("%s: vdd_%s TRANXDONE timeout exceeded."
 488                         "TRANXDONE never got set after the voltage update\n",
 489                         __func__, vdd->voltdm.name);
 490
 491         _post_volt_scale(vdd, target_volt, target_vsel, current_vsel);
 492
 493         /*
 494          * Disable TransactionDone interrupt , clear all status, clear
 495          * control registers
 496          */
 497         timeout = 0;
 498         while (timeout++ < VP_TRANXDONE_TIMEOUT) {
 499                 vdd->write_reg(vdd->vp_data->prm_irqst_data->tranxdone_status,
 500                                prm_irqst_ocp_mod_offs, prm_irqst_reg);
 501                 if (!(vdd->read_reg(prm_irqst_ocp_mod_offs, prm_irqst_reg) &
 502                       vdd->vp_data->prm_irqst_data->tranxdone_status))
 503                         break;
 504                 udelay(1);
 505         }
 506
 507         if (timeout >= VP_TRANXDONE_TIMEOUT)
 508                 pr_warning("%s: vdd_%s TRANXDONE timeout exceeded while trying"
 509                         "to clear the TRANXDONE status\n",
 510                         __func__, vdd->voltdm.name);
 511
 512         vpconfig = vdd->read_reg(prm_mod_offs, vdd->vp_data->vpconfig);
 513         /* Clear initVDD copy trigger bit */
 514         vpconfig &= ~vdd->vp_data->vp_common->vpconfig_initvdd;
 515         vdd->write_reg(vpconfig, prm_mod_offs, vdd->vp_data->vpconfig);
 516         /* Clear force bit */
 517         vpconfig &= ~vdd->vp_data->vp_common->vpconfig_forceupdate;
 518         vdd->write_reg(vpconfig, prm_mod_offs, vdd->vp_data->vpconfig);
 519
 520         return 0;
 521 }
 522
 523 static void __init omap3_vfsm_init(struct omap_vdd_info *vdd)
 524 {
 525         /*
 526          * Voltage Manager FSM parameters init
 527          * XXX This data should be passed in from the board file
 528          */
 529         vdd->write_reg(OMAP3_CLKSETUP, prm_mod_offs, OMAP3_PRM_CLKSETUP_OFFSET);
 530         vdd->write_reg(OMAP3_VOLTOFFSET, prm_mod_offs,
 531                        OMAP3_PRM_VOLTOFFSET_OFFSET);
 532         vdd->write_reg(OMAP3_VOLTSETUP2, prm_mod_offs,
 533                        OMAP3_PRM_VOLTSETUP2_OFFSET);
 534 }
 535
 536 static void __init omap3_vc_init(struct omap_vdd_info *vdd)
 537 {
 538         static bool is_initialized;
 539         u8 on_vsel, onlp_vsel, ret_vsel, off_vsel;
 540         u32 vc_val;
 541
 542         if (is_initialized)
 543                 return;
 544
 545         /* Set up the on, inactive, retention and off voltage */
 546         on_vsel = vdd->pmic_info->uv_to_vsel(vdd->pmic_info->on_volt);
 547         onlp_vsel = vdd->pmic_info->uv_to_vsel(vdd->pmic_info->onlp_volt);
 548         ret_vsel = vdd->pmic_info->uv_to_vsel(vdd->pmic_info->ret_volt);
 549         off_vsel = vdd->pmic_info->uv_to_vsel(vdd->pmic_info->off_volt);
 550         vc_val  = ((on_vsel << vdd->vc_data->vc_common->cmd_on_shift) |
 551                 (onlp_vsel << vdd->vc_data->vc_common->cmd_onlp_shift) |
 552                 (ret_vsel << vdd->vc_data->vc_common->cmd_ret_shift) |
 553                 (off_vsel << vdd->vc_data->vc_common->cmd_off_shift));
 554         vdd->write_reg(vc_val, prm_mod_offs, vdd->vc_data->cmdval_reg);
 555
 556         /*
 557          * Generic VC parameters init
 558          * XXX This data should be abstracted out
 559          */
 560         vdd->write_reg(OMAP3430_CMD1_MASK | OMAP3430_RAV1_MASK, prm_mod_offs,
 561                         OMAP3_PRM_VC_CH_CONF_OFFSET);
 562         vdd->write_reg(OMAP3430_MCODE_SHIFT | OMAP3430_HSEN_MASK, prm_mod_offs,
 563                         OMAP3_PRM_VC_I2C_CFG_OFFSET);
 564
 565         omap3_vfsm_init(vdd);
 566
 567         is_initialized = true;
 568 }
 569
 570
 571 /* OMAP4 specific voltage init functions */
 572 static void __init omap4_vc_init(struct omap_vdd_info *vdd)
 573 {
 574         static bool is_initialized;
 575         u32 vc_val;
 576
 577         if (is_initialized)
 578                 return;
 579
 580         /* TODO: Configure setup times and CMD_VAL values*/
 581
 582         /*
 583          * Generic VC parameters init
 584          * XXX This data should be abstracted out
 585          */
 586         vc_val = (OMAP4430_RAV_VDD_MPU_L_MASK | OMAP4430_CMD_VDD_MPU_L_MASK |
 587                   OMAP4430_RAV_VDD_IVA_L_MASK | OMAP4430_CMD_VDD_IVA_L_MASK |
 588                   OMAP4430_RAV_VDD_CORE_L_MASK | OMAP4430_CMD_VDD_CORE_L_MASK);
 589         vdd->write_reg(vc_val, prm_mod_offs, OMAP4_PRM_VC_CFG_CHANNEL_OFFSET);
 590
 591         /* XXX These are magic numbers and do not belong! */
 592         vc_val = (0x60 << OMAP4430_SCLL_SHIFT | 0x26 << OMAP4430_SCLH_SHIFT);
 593         vdd->write_reg(vc_val, prm_mod_offs, OMAP4_PRM_VC_CFG_I2C_CLK_OFFSET);
 594
 595         is_initialized = true;
 596 }
 597
 598 static void __init omap_vc_init(struct omap_vdd_info *vdd)
 599 {
 600         u32 vc_val;
 601
 602         if (!vdd->pmic_info || !vdd->pmic_info->uv_to_vsel) {
 603                 pr_err("%s: PMIC info requried to configure vc for"
 604                         "vdd_%s not populated.Hence cannot initialize vc\n",
 605                         __func__, vdd->voltdm.name);
 606                 return;
 607         }
 608
 609         if (!vdd->read_reg || !vdd->write_reg) {
 610                 pr_err("%s: No read/write API for accessing vdd_%s regs\n",
 611                         __func__, vdd->voltdm.name);
 612                 return;
 613         }
 614
 615         /* Set up the SMPS_SA(i2c slave address in VC */
 616         vc_val = vdd->read_reg(prm_mod_offs,
 617                                vdd->vc_data->vc_common->smps_sa_reg);
 618         vc_val &= ~vdd->vc_data->smps_sa_mask;
 619         vc_val |= vdd->pmic_info->i2c_slave_addr << vdd->vc_data->smps_sa_shift;
 620         vdd->write_reg(vc_val, prm_mod_offs,
 621                        vdd->vc_data->vc_common->smps_sa_reg);
 622
 623         /* Setup the VOLRA(pmic reg addr) in VC */
 624         vc_val = vdd->read_reg(prm_mod_offs,
 625                                vdd->vc_data->vc_common->smps_volra_reg);
 626         vc_val &= ~vdd->vc_data->smps_volra_mask;
 627         vc_val |= vdd->pmic_info->pmic_reg << vdd->vc_data->smps_volra_shift;
 628         vdd->write_reg(vc_val, prm_mod_offs,
 629                        vdd->vc_data->vc_common->smps_volra_reg);
 630
 631         /* Configure the setup times */
 632         vc_val = vdd->read_reg(prm_mod_offs, vdd->vfsm->voltsetup_reg);
 633         vc_val &= ~vdd->vfsm->voltsetup_mask;
 634         vc_val |= vdd->pmic_info->volt_setup_time <<
 635                         vdd->vfsm->voltsetup_shift;
 636         vdd->write_reg(vc_val, prm_mod_offs, vdd->vfsm->voltsetup_reg);
 637
 638         if (cpu_is_omap34xx())
 639                 omap3_vc_init(vdd);
 640         else if (cpu_is_omap44xx())
 641                 omap4_vc_init(vdd);
 642 }
 643
 644 static int __init omap_vdd_data_configure(struct omap_vdd_info *vdd)
 645 {
 646         int ret = -EINVAL;
 647
 648         if (!vdd->pmic_info) {
 649                 pr_err("%s: PMIC info requried to configure vdd_%s not"
 650                         "populated.Hence cannot initialize vdd_%s\n",
 651                         __func__, vdd->voltdm.name, vdd->voltdm.name);
 652                 goto ovdc_out;
 653         }
 654
 655         if (IS_ERR_VALUE(_config_common_vdd_data(vdd)))
 656                 goto ovdc_out;
 657
 658         if (cpu_is_omap34xx()) {
 659                 vdd->read_reg = omap3_voltage_read_reg;
 660                 vdd->write_reg = omap3_voltage_write_reg;
 661                 ret = 0;
 662         } else if (cpu_is_omap44xx()) {
 663                 vdd->read_reg = omap4_voltage_read_reg;
 664                 vdd->write_reg = omap4_voltage_write_reg;
 665                 ret = 0;
 666         }
 667
 668 ovdc_out:
 669         return ret;
 670 }
 671
 672 /* Public functions */
 673 /**
 674  * omap_voltage_get_nom_volt() - Gets the current non-auto-compensated voltage
 675  * @voltdm:     pointer to the VDD for which current voltage info is needed
 676  *
 677  * API to get the current non-auto-compensated voltage for a VDD.
 678  * Returns 0 in case of error else returns the current voltage for the VDD.
 679  */
 680 unsigned long omap_voltage_get_nom_volt(struct voltagedomain *voltdm)
 681 {
 682         struct omap_vdd_info *vdd;
 683
 684         if (!voltdm || IS_ERR(voltdm)) {
 685                 pr_warning("%s: VDD specified does not exist!\n", __func__);
 686                 return 0;
 687         }
 688
 689         vdd = container_of(voltdm, struct omap_vdd_info, voltdm);
 690
 691         return vdd->curr_volt;
 692 }
 693
 694 /**
 695  * omap_vp_get_curr_volt() - API to get the current vp voltage.
 696  * @voltdm:     pointer to the VDD.
 697  *
 698  * This API returns the current voltage for the specified voltage processor
 699  */
 700 unsigned long omap_vp_get_curr_volt(struct voltagedomain *voltdm)
 701 {
 702         struct omap_vdd_info *vdd;
 703         u8 curr_vsel;
 704
 705         if (!voltdm || IS_ERR(voltdm)) {
 706                 pr_warning("%s: VDD specified does not exist!\n", __func__);
 707                 return 0;
 708         }
 709
 710         vdd = container_of(voltdm, struct omap_vdd_info, voltdm);
 711         if (!vdd->read_reg) {
 712                 pr_err("%s: No read API for reading vdd_%s regs\n",
 713                         __func__, voltdm->name);
 714                 return 0;
 715         }
 716
 717         curr_vsel = vdd->read_reg(prm_mod_offs, vdd->vp_data->voltage);
 718
 719         if (!vdd->pmic_info || !vdd->pmic_info->vsel_to_uv) {
 720                 pr_warning("%s: PMIC function to convert vsel to voltage"
 721                         "in uV not registerd\n", __func__);
 722                 return 0;
 723         }
 724
 725         return vdd->pmic_info->vsel_to_uv(curr_vsel);
 726 }
 727
 728 /**
 729  * omap_vp_enable() - API to enable a particular VP
 730  * @voltdm:     pointer to the VDD whose VP is to be enabled.
 731  *
 732  * This API enables a particular voltage processor. Needed by the smartreflex
 733  * class drivers.
 734  */
 735 void omap_vp_enable(struct voltagedomain *voltdm)
 736 {
 737         struct omap_vdd_info *vdd;
 738         u32 vpconfig;
 739
 740         if (!voltdm || IS_ERR(voltdm)) {
 741                 pr_warning("%s: VDD specified does not exist!\n", __func__);
 742                 return;
 743         }
 744
 745         vdd = container_of(voltdm, struct omap_vdd_info, voltdm);
 746         if (!vdd->read_reg || !vdd->write_reg) {
 747                 pr_err("%s: No read/write API for accessing vdd_%s regs\n",
 748                         __func__, voltdm->name);
 749                 return;
 750         }
 751
 752         /* If VP is already enabled, do nothing. Return */
 753         if (vdd->vp_enabled)
 754                 return;
 755
 756         vp_latch_vsel(vdd);
 757
 758         /* Enable VP */
 759         vpconfig = vdd->read_reg(prm_mod_offs, vdd->vp_data->vpconfig);
 760         vpconfig |= vdd->vp_data->vp_common->vpconfig_vpenable;
 761         vdd->write_reg(vpconfig, prm_mod_offs, vdd->vp_data->vpconfig);
 762         vdd->vp_enabled = true;
 763 }
 764
 765 /**
 766  * omap_vp_disable() - API to disable a particular VP
 767  * @voltdm:     pointer to the VDD whose VP is to be disabled.
 768  *
 769  * This API disables a particular voltage processor. Needed by the smartreflex
 770  * class drivers.
 771  */
 772 void omap_vp_disable(struct voltagedomain *voltdm)
 773 {
 774         struct omap_vdd_info *vdd;
 775         u32 vpconfig;
 776         int timeout;
 777
 778         if (!voltdm || IS_ERR(voltdm)) {
 779                 pr_warning("%s: VDD specified does not exist!\n", __func__);
 780                 return;
 781         }
 782
 783         vdd = container_of(voltdm, struct omap_vdd_info, voltdm);
 784         if (!vdd->read_reg || !vdd->write_reg) {
 785                 pr_err("%s: No read/write API for accessing vdd_%s regs\n",
 786                         __func__, voltdm->name);
 787                 return;
 788         }
 789
 790         /* If VP is already disabled, do nothing. Return */
 791         if (!vdd->vp_enabled) {
 792                 pr_warning("%s: Trying to disable VP for vdd_%s when"
 793                         "it is already disabled\n", __func__, voltdm->name);
 794                 return;
 795         }
 796
 797         /* Disable VP */
 798         vpconfig = vdd->read_reg(prm_mod_offs, vdd->vp_data->vpconfig);
 799         vpconfig &= ~vdd->vp_data->vp_common->vpconfig_vpenable;
 800         vdd->write_reg(vpconfig, prm_mod_offs, vdd->vp_data->vpconfig);
 801
 802         /*
 803          * Wait for VP idle Typical latency is <2us. Maximum latency is ~100us
 804          */
 805         omap_test_timeout((vdd->read_reg(prm_mod_offs, vdd->vp_data->vstatus)),
 806                                 VP_IDLE_TIMEOUT, timeout);
 807
 808         if (timeout >= VP_IDLE_TIMEOUT)
 809                 pr_warning("%s: vdd_%s idle timedout\n",
 810                         __func__, voltdm->name);
 811
 812         vdd->vp_enabled = false;
 813
 814         return;
 815 }
 816
 817 /**
 818  * omap_voltage_scale_vdd() - API to scale voltage of a particular
 819  *                              voltage domain.
 820  * @voltdm:     pointer to the VDD which is to be scaled.
 821  * @target_volt:        The target voltage of the voltage domain
 822  *
 823  * This API should be called by the kernel to do the voltage scaling
 824  * for a particular voltage domain during dvfs or any other situation.
 825  */
 826 int omap_voltage_scale_vdd(struct voltagedomain *voltdm,
 827                 unsigned long target_volt)
 828 {
 829         struct omap_vdd_info *vdd;
 830
 831         if (!voltdm || IS_ERR(voltdm)) {
 832                 pr_warning("%s: VDD specified does not exist!\n", __func__);
 833                 return -EINVAL;
 834         }
 835
 836         vdd = container_of(voltdm, struct omap_vdd_info, voltdm);
 837
 838         if (!vdd->volt_scale) {
 839                 pr_err("%s: No voltage scale API registered for vdd_%s\n",
 840                         __func__, voltdm->name);
 841                 return -ENODATA;
 842         }
 843
 844         return vdd->volt_scale(vdd, target_volt);
 845 }
 846
 847 /**
 848  * omap_voltage_reset() - Resets the voltage of a particular voltage domain
 849  *                      to that of the current OPP.
 850  * @voltdm:     pointer to the VDD whose voltage is to be reset.
 851  *
 852  * This API finds out the correct voltage the voltage domain is supposed
 853  * to be at and resets the voltage to that level. Should be used especially
 854  * while disabling any voltage compensation modules.
 855  */
 856 void omap_voltage_reset(struct voltagedomain *voltdm)
 857 {
 858         unsigned long target_uvdc;
 859
 860         if (!voltdm || IS_ERR(voltdm)) {
 861                 pr_warning("%s: VDD specified does not exist!\n", __func__);
 862                 return;
 863         }
 864
 865         target_uvdc = omap_voltage_get_nom_volt(voltdm);
 866         if (!target_uvdc) {
 867                 pr_err("%s: unable to find current voltage for vdd_%s\n",
 868                         __func__, voltdm->name);
 869                 return;
 870         }
 871
 872         omap_voltage_scale_vdd(voltdm, target_uvdc);
 873 }
 874
 875 /**
 876  * omap_voltage_get_volttable() - API to get the voltage table associated with a
 877  *                              particular voltage domain.
 878  * @voltdm:     pointer to the VDD for which the voltage table is required
 879  * @volt_data:  the voltage table for the particular vdd which is to be
 880  *              populated by this API
 881  *
 882  * This API populates the voltage table associated with a VDD into the
 883  * passed parameter pointer. Returns the count of distinct voltages
 884  * supported by this vdd.
 885  *
 886  */
 887 void omap_voltage_get_volttable(struct voltagedomain *voltdm,
 888                 struct omap_volt_data **volt_data)
 889 {
 890         struct omap_vdd_info *vdd;
 891
 892         if (!voltdm || IS_ERR(voltdm)) {
 893                 pr_warning("%s: VDD specified does not exist!\n", __func__);
 894                 return;
 895         }
 896
 897         vdd = container_of(voltdm, struct omap_vdd_info, voltdm);
 898
 899         *volt_data = vdd->volt_data;
 900 }
 901
 902 /**
 903  * omap_voltage_get_voltdata() - API to get the voltage table entry for a
 904  *                              particular voltage
 905  * @voltdm:     pointer to the VDD whose voltage table has to be searched
 906  * @volt:       the voltage to be searched in the voltage table
 907  *
 908  * This API searches through the voltage table for the required voltage
 909  * domain and tries to find a matching entry for the passed voltage volt.
 910  * If a matching entry is found volt_data is populated with that entry.
 911  * This API searches only through the non-compensated voltages int the
 912  * voltage table.
 913  * Returns pointer to the voltage table entry corresponding to volt on
 914  * success. Returns -ENODATA if no voltage table exisits for the passed voltage
 915  * domain or if there is no matching entry.
 916  */
 917 struct omap_volt_data *omap_voltage_get_voltdata(struct voltagedomain *voltdm,
 918                 unsigned long volt)
 919 {
 920         struct omap_vdd_info *vdd;
 921         int i;
 922
 923         if (!voltdm || IS_ERR(voltdm)) {
 924                 pr_warning("%s: VDD specified does not exist!\n", __func__);
 925                 return ERR_PTR(-EINVAL);
 926         }
 927
 928         vdd = container_of(voltdm, struct omap_vdd_info, voltdm);
 929
 930         if (!vdd->volt_data) {
 931                 pr_warning("%s: voltage table does not exist for vdd_%s\n",
 932                         __func__, voltdm->name);
 933                 return ERR_PTR(-ENODATA);
 934         }
 935
 936         for (i = 0; vdd->volt_data[i].volt_nominal != 0; i++) {
 937                 if (vdd->volt_data[i].volt_nominal == volt)
 938                         return &vdd->volt_data[i];
 939         }
 940
 941         pr_notice("%s: Unable to match the current voltage with the voltage"
 942                 "table for vdd_%s\n", __func__, voltdm->name);
 943
 944         return ERR_PTR(-ENODATA);
 945 }
 946
 947 /**
 948  * omap_voltage_register_pmic() - API to register PMIC specific data
 949  * @voltdm:     pointer to the VDD for which the PMIC specific data is
 950  *              to be registered
 951  * @pmic_info:  the structure containing pmic info
 952  *
 953  * This API is to be called by the SOC/PMIC file to specify the
 954  * pmic specific info as present in omap_volt_pmic_info structure.
 955  */
 956 int omap_voltage_register_pmic(struct voltagedomain *voltdm,
 957                 struct omap_volt_pmic_info *pmic_info)
 958 {
 959         struct omap_vdd_info *vdd;
 960
 961         if (!voltdm || IS_ERR(voltdm)) {
 962                 pr_warning("%s: VDD specified does not exist!\n", __func__);
 963                 return -EINVAL;
 964         }
 965
 966         vdd = container_of(voltdm, struct omap_vdd_info, voltdm);
 967
 968         vdd->pmic_info = pmic_info;
 969
 970         return 0;
 971 }
 972
 973 /**
 974  * omap_voltage_get_dbgdir() - API to get pointer to the debugfs directory
 975  *                              corresponding to a voltage domain.
 976  *
 977  * @voltdm:     pointer to the VDD whose debug directory is required.
 978  *
 979  * This API returns pointer to the debugfs directory corresponding
 980  * to the voltage domain. Should be used by drivers requiring to
 981  * add any debug entry for a particular voltage domain. Returns NULL
 982  * in case of error.
 983  */
 984 struct dentry *omap_voltage_get_dbgdir(struct voltagedomain *voltdm)
 985 {
 986         struct omap_vdd_info *vdd;
 987
 988         if (!voltdm || IS_ERR(voltdm)) {
 989                 pr_warning("%s: VDD specified does not exist!\n", __func__);
 990                 return NULL;
 991         }
 992
 993         vdd = container_of(voltdm, struct omap_vdd_info, voltdm);
 994
 995         return vdd->debug_dir;
 996 }
 997
 998 /**
 999  * omap_change_voltscale_method() - API to change the voltage scaling method.
1000  * @voltdm:     pointer to the VDD whose voltage scaling method
1001  *              has to be changed.
1002  * @voltscale_method:   the method to be used for voltage scaling.
1003  *
1004  * This API can be used by the board files to change the method of voltage
1005  * scaling between vpforceupdate and vcbypass. The parameter values are
1006  * defined in voltage.h
1007  */
1008 void omap_change_voltscale_method(struct voltagedomain *voltdm,
1009                 int voltscale_method)
1010 {
1011         struct omap_vdd_info *vdd;
1012
1013         if (!voltdm || IS_ERR(voltdm)) {
1014                 pr_warning("%s: VDD specified does not exist!\n", __func__);
1015                 return;
1016         }
1017
1018         vdd = container_of(voltdm, struct omap_vdd_info, voltdm);
1019
1020         switch (voltscale_method) {
1021         case VOLTSCALE_VPFORCEUPDATE:
1022                 vdd->volt_scale = vp_forceupdate_scale_voltage;
1023                 return;
1024         case VOLTSCALE_VCBYPASS:
1025                 vdd->volt_scale = vc_bypass_scale_voltage;
1026                 return;
1027         default:
1028                 pr_warning("%s: Trying to change the method of voltage scaling"
1029                         "to an unsupported one!\n", __func__);
1030         }
1031 }
1032
1033 /**
1034  * omap_voltage_domain_lookup() - API to get the voltage domain pointer
1035  * @name:       Name of the voltage domain
1036  *
1037  * This API looks up in the global vdd_info struct for the
1038  * existence of voltage domain <name>. If it exists, the API returns
1039  * a pointer to the voltage domain structure corresponding to the
1040  * VDD<name>. Else retuns error pointer.
1041  */
1042 struct voltagedomain *omap_voltage_domain_lookup(char *name)
1043 {
1044         int i;
1045
1046         if (!vdd_info) {
1047                 pr_err("%s: Voltage driver init not yet happened.Faulting!\n",
1048                         __func__);
1049                 return ERR_PTR(-EINVAL);
1050         }
1051
1052         if (!name) {
1053                 pr_err("%s: No name to get the votage domain!\n", __func__);
1054                 return ERR_PTR(-EINVAL);
1055         }
1056
1057         for (i = 0; i < nr_scalable_vdd; i++) {
1058                 if (!(strcmp(name, vdd_info[i]->voltdm.name)))
1059                         return &vdd_info[i]->voltdm;
1060         }
1061
1062         return ERR_PTR(-EINVAL);
1063 }
1064
1065 /**
1066  * omap_voltage_late_init() - Init the various voltage parameters
1067  *
1068  * This API is to be called in the later stages of the
1069  * system boot to init the voltage controller and
1070  * voltage processors.
1071  */
1072 int __init omap_voltage_late_init(void)
1073 {
1074         int i;
1075
1076         if (!vdd_info) {
1077                 pr_err("%s: Voltage driver support not added\n",
1078                         __func__);
1079                 return -EINVAL;
1080         }
1081
1082         voltage_dir = debugfs_create_dir("voltage", NULL);
1083         if (IS_ERR(voltage_dir))
1084                 pr_err("%s: Unable to create voltage debugfs main dir\n",
1085                         __func__);
1086         for (i = 0; i < nr_scalable_vdd; i++) {
1087                 if (omap_vdd_data_configure(vdd_info[i]))
1088                         continue;
1089                 omap_vc_init(vdd_info[i]);
1090                 vp_init(vdd_info[i]);
1091                 vdd_debugfs_init(vdd_info[i]);
1092         }
1093
1094         return 0;
1095 }
1096
1097 /* XXX document */
1098 int __init omap_voltage_early_init(s16 prm_mod, s16 prm_irqst_ocp_mod,
1099                                    struct omap_vdd_info *omap_vdd_array[],
1100                                    u8 omap_vdd_count)
1101 {
1102         prm_mod_offs = prm_mod;
1103         prm_irqst_ocp_mod_offs = prm_irqst_ocp_mod;
1104         vdd_info = omap_vdd_array;
1105         nr_scalable_vdd = omap_vdd_count;
1106         return 0;
1107 }